The present invention generally relates to a storage system, and in particular is suitable for application in a storage system that duplicates data.
Technology for duplicating data in order to improve the reliability of data storage in a storage system is known. As data duplication technology, known is a system comprising a processor for executing an application program and an operating system, a host system for issuing an original data write/read command, a data multiplexer connected to the host system, and first and second storage systems respectively connected to the data multiplexer and which store data for the host system, wherein data is duplicated by the host system writing data in the first and second storage systems (for instance, refer to Japanese Patent Laid-Open Publication No. 2006-154880).